Hi Divyansh Thakkar.

Based on my own understanding, 150 x 150 x 150 cube size is not the only size available. There are also cube sizes of 50 x 50 x 50, 100 x 100 x 100mm and cylinder sizes of 150 x 300mm, 100 x 200mm. According to the research carried out on the

**'Effect of Cube size on the Compressive Strength of Concrete by 'Misba Gul'', **the cube size of 150 x 150 x 150mm represented the sizes that are most commonly used locally and universally in the construction research. It is true that the use of 100 x 100 x100mm cube size has greater advantages in the sense that, it is easier to handle, it saves materials, it needs smaller space for curing and storage, as well as lesser labor and time, but the Engineers and Architects are still reluctant in using 100mm cubes for determining the compressive strength of concrete because of the perceived greater variability in their compressive strengths over that of the 150mm cubes. In the research results, it was observed that the compressive strength of concrete on 100mm cubes was between 5% to 6% higher than that of 150mm cubes at the age of 28days. Which means that, if you happen to use 100mm cubes, the values obtained should be reduced by 5% to 6% to achieve the

**Actual Characteristic Strength.** Of course, this may look tedious.

**There is also lack of compliance criteria for the 100mm cubes as the general specification provides acceptance criteria based on 150mm cube strengths only. **This is why, in this situation, 150 x 150 x 150mm cube is always used.

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Anthony Ekwuno PMP, CT, Aff.M.ASCE

Professional Engineering Technologist

FT Consultants

Pretoria

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Original Message:

Sent: 06-14-2017 01:38

From: Divyansh Thakkar

Subject: Workability of concrete and compressive test

**Hey ASCE Collaborate,**
I am in my 1st year of studies and I am having trouble understanding workability of concrete and compressive tests, where we take concrete cubes in the size of 150mm×150mm×150mm. Why are these the only dimensions taken?

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Divyansh Thakkar S.M.ASCE

Student

Bhopal MP

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